To determine instantaneous position, signals are evaluated from several satellites, which revolve around the earth on fixed, predetermined orbits. On the basis of delay measurements, a receiver can determine the exact distance to the satellite, whose current position is known in the receiver (for example, from data transmitted by the satellite to the receiver). The information received as to the position of three satellites and the distance to them is sufficient to allow an exact and clear determination of the location of the receiver within an accuracy range of a few meters. If the receiver is located, for example, in a motor vehicle, whose vehicle parts partially shadow, i.e., block, the receiving range, then not all satellites seemingly suited for determining position can be received. On the other hand, due to reflections off of house walls or hills, it can happen that satellite signals, which simulate a false satellite position, are received. The receiver itself, however, is not able to differentiate among these different signals, so that incorrect position determinations are sometimes made. Such incorrect determinations are not desirable, since they can adversely affect the reliability of the device to a considerable extent.